Authenticated server crash via deferred schema validation
Published May 30, 2025 · Updated May 30, 2025
Denial of service in vLLM 0.8.0 and later before 0.9.0 allows remote authenticated users to crash the server with guided JSON. The structured-output path defers XGrammar parsing until engine scheduling, where an invalid schema raises an uncaught RuntimeError. Low-privileged API access is required; one crafted completion request terminates worker processes and interrupts inference without reading or altering data.
Summary
What happened
Denial of service in vLLM 0.8.0 and later before 0.9.0 allows remote authenticated users to crash the server with guided JSON. The structured-output path defers XGrammar parsing until engine scheduling, where an invalid schema raises an uncaught RuntimeError. Low-privileged API access is required; one crafted completion request terminates worker processes and interrupts inference without reading or altering data.
The record
- CVE
- CVE-2025-48942
- Published
- May 30, 2025
- Updated
- May 30, 2025
- Vendor
- vLLM Project
- Product
- vLLM
- Classifications
- CWE-248, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 30, 2025CVE publishedPublication date reported by the CVE source.
- May 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>= 0.8.0, < 0.9.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Upstream invalid guided-JSON proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo